[RFI] Internet Modem / Router Cable Length and RFI

[Jim Brown]

On Mon,6/1/2015 8:10 PM, KD7JYK DM09 wrote:
> "I would worry more about the long cat5 cable, both for rfi and
> susceptibility to your rf getting into it."
>
> Anyone running CAT5 through EMT?  Looking at the possibility of a 30-40' run
> under the house and thinking of running it through a grounded pipe from the
> router to the computer with only a few inches exposed at each end.

I love EMT for shielding.  BUT -- to provide shielding, the EMT, like 
any cable shield, must be bonded to the shielding enclosure (or ground 
plane) of the equipment at both ends. Simply grounding the EMT is 
insufficient.

Another potential issue -- engineers working in computer networking 
advise many practices that we use for analog systems should not be used 
for unshielded CAT5/6/7 cables. We should not, for example, bundle them, 
because it creates small discontinuities in the balance of the pairs, 
and of the coupling between pairs.  Putting these cables in EMT could 
have the same effect. The result is increased error rates, thus slower 
data rates.

73, Jim K9YC